31 lines
1.1 KiB
JavaScript
31 lines
1.1 KiB
JavaScript
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'use strict';
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var $ = require('../internals/export');
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var toInteger = require('../internals/to-integer');
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var parseInt = require('../internals/number-parse-int');
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var INVALID_NUMBER_REPRESENTATION = 'Invalid number representation';
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var INVALID_RADIX = 'Invalid radix';
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var valid = /^[\da-z]+$/;
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// `Number.fromString` method
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// https://github.com/tc39/proposal-number-fromstring
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$({ target: 'Number', stat: true }, {
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fromString: function fromString(string, radix) {
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var sign = 1;
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var R, mathNum;
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if (typeof string != 'string') throw TypeError(INVALID_NUMBER_REPRESENTATION);
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if (!string.length) throw SyntaxError(INVALID_NUMBER_REPRESENTATION);
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if (string.charAt(0) == '-') {
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sign = -1;
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string = string.slice(1);
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if (!string.length) throw SyntaxError(INVALID_NUMBER_REPRESENTATION);
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}
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R = radix === undefined ? 10 : toInteger(radix);
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if (R < 2 || R > 36) throw RangeError(INVALID_RADIX);
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if (!valid.test(string) || (mathNum = parseInt(string, R)).toString(R) !== string) {
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throw SyntaxError(INVALID_NUMBER_REPRESENTATION);
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}
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return sign * mathNum;
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}
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});
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